@R2D2: Yes, this prototype still has a far way to go. Still, to idea is cool enough to make it into this week's (lighter) news:

Kazu Terasaki, a Japanese software engineer working in the Silicon Valley area, has created a walking iPhone robot. Using two servo motors in combination with small metal paddles the robot can raise itself and shuffle its feet.

Unfortunately the current prototype can hardly be called useful. However, Terasaki is already on his way to pursue a wider goal, developing a kit of robot legs that you can attach to absolutely anything.